This invention relates to movement of containerized and palletized cargo into modern wide body cargo aircraft; and, more particularly to a method and apparatus for movement of such cargo through an aircraft door having a width substantially smaller than the length of the palletized cargo.
The need for mechanization of cargo movement is particularly acute in the field of air transported cargo. Cargo space is often a limiting factor and the mechanization allows better utilization of whatever cargo space is available since clearances to allow access for personnel can be reduced to a minimum. Utilization of the aircraft is enhanced because loading and unloading takes less time. This is important because of the relatively high cost of "down-time" for airplanes. Also, a prime asset of carrying cargo by air is the time saved and therefore any saving in handling time is of importance.
Some airplane designs are dedicated to air cargo carrying and these airplanes usually provide "straight in" access to the cargo volume through the nose or tail of the fuselage to achieve the optimum conditions for rapid, automated loading and unloading. However, on some route structures the most economical approach is to use an airplane which carries both passengers and cargo. The cargo carrying role of these airplanes does not justify the expense and complication of nose and/or tail access and, also, the passenger compartment can interfere with straight in loading and unloading. Therefore, side-of-body cargo doors are provided. Furthermore, in some cases there are economic advantages to be gained by using side cargo doors along with nose and/or tail access. These doors provided added unloading and loading capability and facilitate the partial loading and unloading occasioned by multi-stop routes.
Another facet important to the economics of shipping containerized and palletized cargo is that shifting from one mode (like ship) to another (like air) should not involve the time and expense of taking the cargo from the ship's containers (or pallets) for the airplane. In other words, the containers and pallets are used interchangeably on all modes of transport. These standardized containers are 8 feet wide and their lengths are in multiples of 10 feet; i.e. 10 feet, 20 feet, 30 feet and 40 feet.
The "8 by 20" containers are in common use today. On the above-mentioned airplanes, which use side cargo doors and cargo bays slightly wider than two containers width (16 +), loading and unloading 8 foot by 20 foot containers presents a problem. The 10 feet pluse door width prevents loading the container sidewise and providing doors 20 feet plus wide is structurally unacceptable. In any event, only a portion of the cargo requires such width. Also, loading the container laterally onto the aircraft presents problems because its 20 foot length exceeds the 16 foot plus width of the cargo floor. The subject invention solves this problem. Furthermore, as required by practical and economic factors, it does so with a minimum of additions and modifications of apparatus and controls already provided for handling the eight foot by ten foot cargo units.